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Overexpression of 17β-hydroxysteroid dehydrogenase type 10 increases pheochromocytoma cell growth and resistance to cell death.

Carlson EA, Marquez RT, Du F, Wang Y, Xu L, Yan SS - BMC Cancer (2015)

Bottom Line: Across disease states, increased HSD10 levels can have a profound and varied impact, such as beneficial in Parkinson's disease and harmful in Alzheimer's disease.In this study, we examined the tumor-promoting effect of HSD10 in pheochromocytoma cells.Our findings demonstrate that overexpression of HSD10 accelerates pheochromocytoma cell growth, enhances cell respiration, and increases cellular resistance to cell death induction.

View Article: PubMed Central - PubMed

Affiliation: Department of Pharmacology & Toxicology, University of Kansas, Lawrence, KS, 66047, USA. e086c574@ku.edu.

ABSTRACT

Background: 17β-hydroxysteroid dehydrogenase type 10 (HSD10) has been shown to play a protective role in cells undergoing stress. Upregulation of HSD10 under nutrient-limiting conditions leads to recovery of a homeostatic state. Across disease states, increased HSD10 levels can have a profound and varied impact, such as beneficial in Parkinson's disease and harmful in Alzheimer's disease. Recently, HSD10 overexpression has been observed in some prostate and bone cancers, consistently correlating with poor patient prognosis. As the role of HSD10 in cancer remains underexplored, we propose that cancer cells utilize this enzyme to promote cancer cell survival under cell death conditions.

Methods: The proliferative effect of HSD10 was examined in transfected pheochromocytoma cells by growth curve analysis and a xenograft model. Fluctuations in mitochondrial bioenergetics were evaluated by electron transport chain complex enzyme activity assays and energy production. Additionally, the effect of HSD10 on pheochromocytoma resistance to cell death was investigated using TUNEL staining, MTT, and complex IV enzyme activity assays.

Results: In this study, we examined the tumor-promoting effect of HSD10 in pheochromocytoma cells. Overexpression of HSD10 increased pheochromocytoma cell growth in both in vitro cell culture and an in vivo xenograft mouse model. The increases in respiratory enzymes and energy generation observed in HSD10-overexpressing cells likely supported the accelerated growth rate observed. Furthermore, cells overexpressing HSD10 were more resistant to oxidative stress-induced perturbation.

Conclusions: Our findings demonstrate that overexpression of HSD10 accelerates pheochromocytoma cell growth, enhances cell respiration, and increases cellular resistance to cell death induction. This suggests that blockade of HSD10 may halt and/or prevent cancer growth, thus providing a promising novel target for cancer patients as a screening or therapeutic option.

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Assessment of mitochondrial bioenergetics in HSD10-transfected cell lines. Electron transport chain complex I (A), II (B), III (C), and IV (D) enzyme activities were assessed in EV, HSD10 ov, control shRNA, and HSD10 shRNA cells. Results, displayed as fold increase (n = 5 for each assay), showed that complex IV activity is enhanced in HSD10 ov cells and all ETC. complex activities are decreased in HSD10 shRNA cells. E. Densitometry of citrate synthase enzyme activity (n = 5) showed no change in activity between EV and HSD10 ov cells, and reduced activity in HSD10 shRNA cells. F. Densitometry of ATP activity (n = 6) demonstrated that ATP levels are increased in HSD10 ov cells and diminished in HSD10 shRNA cells. G. Densitometry of MTT reduction (n = 4) exhibited similar reduction of MTT by all HSD10-transfected cell lines. Data presented as mean ± SE. *P < 0.01, **P < 0.001, ***P < 0.0001 versus EV and control shRNA groups.
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Fig2: Assessment of mitochondrial bioenergetics in HSD10-transfected cell lines. Electron transport chain complex I (A), II (B), III (C), and IV (D) enzyme activities were assessed in EV, HSD10 ov, control shRNA, and HSD10 shRNA cells. Results, displayed as fold increase (n = 5 for each assay), showed that complex IV activity is enhanced in HSD10 ov cells and all ETC. complex activities are decreased in HSD10 shRNA cells. E. Densitometry of citrate synthase enzyme activity (n = 5) showed no change in activity between EV and HSD10 ov cells, and reduced activity in HSD10 shRNA cells. F. Densitometry of ATP activity (n = 6) demonstrated that ATP levels are increased in HSD10 ov cells and diminished in HSD10 shRNA cells. G. Densitometry of MTT reduction (n = 4) exhibited similar reduction of MTT by all HSD10-transfected cell lines. Data presented as mean ± SE. *P < 0.01, **P < 0.001, ***P < 0.0001 versus EV and control shRNA groups.

Mentions: To examine the effect of HSD10 on mitochondrial function, we assessed the enzyme activities of complexes I, II, III, and IV of the electron transport chain (ETC.). Complexes I, III, and IV are proton pumps, which generate the transmembrane proton gradient necessary to drive ATP generation by ATP synthase. Any changes in the ETC. system would impact mitochondrial ATP generation and any ensuing mitochondrial processes. While the enzyme activities of complexes I, II, and III remained unchanged (Figure 2A-C), complex IV activity was significantly increased in HSD10 ov cells compared with EV cells (Figure 2D), suggesting an enhancement in the ETC. system of HSD10-overexpressing cells. Conversely, HSD10 shRNA cells displayed significantly decreased ETC. complex enzyme activity in all of the complexes measured, in comparison to control shRNA cells (Figure 2A-D). This reduction in all of the complexes indicates that HSD10 is important for cancer cell functionality, and would likely have a substantial impact on subsequent mitochondrial processes.Figure 2


Overexpression of 17β-hydroxysteroid dehydrogenase type 10 increases pheochromocytoma cell growth and resistance to cell death.

Carlson EA, Marquez RT, Du F, Wang Y, Xu L, Yan SS - BMC Cancer (2015)

Assessment of mitochondrial bioenergetics in HSD10-transfected cell lines. Electron transport chain complex I (A), II (B), III (C), and IV (D) enzyme activities were assessed in EV, HSD10 ov, control shRNA, and HSD10 shRNA cells. Results, displayed as fold increase (n = 5 for each assay), showed that complex IV activity is enhanced in HSD10 ov cells and all ETC. complex activities are decreased in HSD10 shRNA cells. E. Densitometry of citrate synthase enzyme activity (n = 5) showed no change in activity between EV and HSD10 ov cells, and reduced activity in HSD10 shRNA cells. F. Densitometry of ATP activity (n = 6) demonstrated that ATP levels are increased in HSD10 ov cells and diminished in HSD10 shRNA cells. G. Densitometry of MTT reduction (n = 4) exhibited similar reduction of MTT by all HSD10-transfected cell lines. Data presented as mean ± SE. *P < 0.01, **P < 0.001, ***P < 0.0001 versus EV and control shRNA groups.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4384325&req=5

Fig2: Assessment of mitochondrial bioenergetics in HSD10-transfected cell lines. Electron transport chain complex I (A), II (B), III (C), and IV (D) enzyme activities were assessed in EV, HSD10 ov, control shRNA, and HSD10 shRNA cells. Results, displayed as fold increase (n = 5 for each assay), showed that complex IV activity is enhanced in HSD10 ov cells and all ETC. complex activities are decreased in HSD10 shRNA cells. E. Densitometry of citrate synthase enzyme activity (n = 5) showed no change in activity between EV and HSD10 ov cells, and reduced activity in HSD10 shRNA cells. F. Densitometry of ATP activity (n = 6) demonstrated that ATP levels are increased in HSD10 ov cells and diminished in HSD10 shRNA cells. G. Densitometry of MTT reduction (n = 4) exhibited similar reduction of MTT by all HSD10-transfected cell lines. Data presented as mean ± SE. *P < 0.01, **P < 0.001, ***P < 0.0001 versus EV and control shRNA groups.
Mentions: To examine the effect of HSD10 on mitochondrial function, we assessed the enzyme activities of complexes I, II, III, and IV of the electron transport chain (ETC.). Complexes I, III, and IV are proton pumps, which generate the transmembrane proton gradient necessary to drive ATP generation by ATP synthase. Any changes in the ETC. system would impact mitochondrial ATP generation and any ensuing mitochondrial processes. While the enzyme activities of complexes I, II, and III remained unchanged (Figure 2A-C), complex IV activity was significantly increased in HSD10 ov cells compared with EV cells (Figure 2D), suggesting an enhancement in the ETC. system of HSD10-overexpressing cells. Conversely, HSD10 shRNA cells displayed significantly decreased ETC. complex enzyme activity in all of the complexes measured, in comparison to control shRNA cells (Figure 2A-D). This reduction in all of the complexes indicates that HSD10 is important for cancer cell functionality, and would likely have a substantial impact on subsequent mitochondrial processes.Figure 2

Bottom Line: Across disease states, increased HSD10 levels can have a profound and varied impact, such as beneficial in Parkinson's disease and harmful in Alzheimer's disease.In this study, we examined the tumor-promoting effect of HSD10 in pheochromocytoma cells.Our findings demonstrate that overexpression of HSD10 accelerates pheochromocytoma cell growth, enhances cell respiration, and increases cellular resistance to cell death induction.

View Article: PubMed Central - PubMed

Affiliation: Department of Pharmacology & Toxicology, University of Kansas, Lawrence, KS, 66047, USA. e086c574@ku.edu.

ABSTRACT

Background: 17β-hydroxysteroid dehydrogenase type 10 (HSD10) has been shown to play a protective role in cells undergoing stress. Upregulation of HSD10 under nutrient-limiting conditions leads to recovery of a homeostatic state. Across disease states, increased HSD10 levels can have a profound and varied impact, such as beneficial in Parkinson's disease and harmful in Alzheimer's disease. Recently, HSD10 overexpression has been observed in some prostate and bone cancers, consistently correlating with poor patient prognosis. As the role of HSD10 in cancer remains underexplored, we propose that cancer cells utilize this enzyme to promote cancer cell survival under cell death conditions.

Methods: The proliferative effect of HSD10 was examined in transfected pheochromocytoma cells by growth curve analysis and a xenograft model. Fluctuations in mitochondrial bioenergetics were evaluated by electron transport chain complex enzyme activity assays and energy production. Additionally, the effect of HSD10 on pheochromocytoma resistance to cell death was investigated using TUNEL staining, MTT, and complex IV enzyme activity assays.

Results: In this study, we examined the tumor-promoting effect of HSD10 in pheochromocytoma cells. Overexpression of HSD10 increased pheochromocytoma cell growth in both in vitro cell culture and an in vivo xenograft mouse model. The increases in respiratory enzymes and energy generation observed in HSD10-overexpressing cells likely supported the accelerated growth rate observed. Furthermore, cells overexpressing HSD10 were more resistant to oxidative stress-induced perturbation.

Conclusions: Our findings demonstrate that overexpression of HSD10 accelerates pheochromocytoma cell growth, enhances cell respiration, and increases cellular resistance to cell death induction. This suggests that blockade of HSD10 may halt and/or prevent cancer growth, thus providing a promising novel target for cancer patients as a screening or therapeutic option.

Show MeSH
Related in: MedlinePlus